Mask assembly, apparatus and method of manufacturing display device using the same, and display device

ABSTRACT

Provided are a display device, a mask assembly, and an apparatus and a method for manufacturing the display device. The mask assembly includes: a mask frame; at least two mask sheets installed on the mask frame, each of the mask sheets including a plurality of openings; and at least two thin shielding plates installed on the mask frame such that the thin shielding plates are spaced apart from each other and shield a portion of the plurality of openings of each mask sheet, wherein one of the mask sheets and the thin shielding plates includes a shielding portion between the thin shielding plates spaced apart from each other, the shielding portion selectively blocking at least portions of the openings so as to form a deposition region having a shape other than a rectangle or a square.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 15/651,808 filed on Jul. 17, 2017, which claims priority under35 USC § 119 to Korean Patent Application No. 10-2016-0100880 filed onAug. 8, 2016 in the Korean Intellectual Property Office, the disclosuresof which are incorporated herein in their entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate generally to display devices, and moreparticularly, to a mask assembly, a method and an apparatus formanufacturing a display device using the same, for a display device.

2. Description of the Related Art

Mobile electronic devices are now widely used. Examples of such mobileelectronic devices are tablet personal computers (PCs), as well asminiaturized electronic devices such as mobile phones.

To support various functions, the mobile electronic apparatus includes adisplay device in order to provide visual information, such as an image,to a user. As parts that make up display devices have becomeminiaturized, the importance of display devices within electronicdevices has gradually increased, leading to the development ofstructures for displays that may be bent from a flat state to have apredetermined angle.

SUMMARY

In the case where a mask assembly of the related art is used, a displayarea may be manufactured only in the shape of a rectangle or a square,and thus there may be difficulty in applying the display area to variousproducts.

One or more embodiments include a mask assembly that may be used tomanufacture display devices in various shapes, a method and an apparatusfor manufacturing a display device, and the display device.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, a mask assembly includes: a maskframe; at least two mask sheets installed on the mask frame, each of themask sheets including a plurality of openings; and at least two thinshielding plates installed on the mask frame such that the thinshielding plates are spaced apart from each other and shield a portionof the plurality of openings of each mask sheet, wherein one of the masksheets and the thin shielding plates includes a shielding portionbetween the thin shielding plates spaced apart from each other, theshielding portion selectively blocking at least portions of the openingsso as to form a deposition region having a shape other than a rectangleor a square.

The shielding portion may include a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion.

The shielding portion may include a second shielding portion shielding aportion of the plurality of openings in the deposition region, the masksheet comprising the second shielding portion.

The shielding portion may include: a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion; and a second shielding portion shielding a portion of theplurality of openings in the deposition region, the mask sheetcomprising the second shielding portion.

The first shielding portion may at least partially overlap the secondshielding portion.

At least a portion of the second shielding portion may have a thicknessless than that of the mask sheet.

The shielding portion may shield at least a portion of at least oneopening at a boundary of the deposition region.

The mask sheet may comprise a first material and the thin shieldingplate may comprise a second material different from the first material.

According to one or more embodiments, an apparatus for manufacturing adisplay device includes: a mask assembly; a source unit facing the maskassembly and configured to supply a deposition material; and a magneticfield generating unit configured to direct the mask assembly toward adisplay substrate. The mask assembly includes: a mask frame; at leasttwo mask sheets installed on the mask frame, each of the mask sheetsincluding a plurality of openings; and at least two thin shieldingplates installed on the mask frame such that the thin shielding platesare spaced apart from each other and shield a portion of the pluralityof openings of each mask sheet, wherein one of the mask sheets and thethin shielding plates includes a shielding portion between the thinshielding plates spaced apart from each other, the shielding portionselectively blocking at least portions of the openings so as to form adeposition region having a shape other than a rectangle or a square.

The shielding portion may include a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion.

The shielding portion may include a second shielding portion provided inthe mask sheet and shielding a portion of the plurality of openings inthe deposition region. The mask sheet may comprise the second shieldingportion.

The shielding portion may include: a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion; and a second shielding portion shielding a portion of theplurality of openings in the deposition region. The mask sheet maycomprise the second shielding portion.

The first shielding portion may at least partially overlap the secondshielding portion.

At least a portion of the second shielding portion may have a thicknessless than that of the mask sheet.

The mask sheet may comprise a first material and the thin shieldingplate may comprise a second material different from the first material.

According to one or more embodiments, a method of manufacturing adisplay device includes: arranging a mask assembly such that the maskassembly faces a display substrate; applying a force to the maskassembly and directed toward the display substrate by using a magneticfield generating unit; and emitting a deposition material from a sourceunit to allow the deposition material to pass through the mask assembly,and depositing the deposition material on the display substrate. Themask assembly includes: a mask frame; at least two mask sheets installedon the mask frame, each of the mask sheets including a plurality ofopenings; and at least two thin shielding plates installed on the maskframe such that the thin shielding plates are spaced apart from eachother and shield a portion of the plurality of openings of each masksheet, wherein one of the mask sheets and the thin shielding platesincludes a shielding portion between the thin shielding plates spacedapart from each other, the shielding portion selectively blocking atleast portions of the openings so as to form a deposition region havinga shape other than a rectangle or a square.

The shielding portion may include a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion.

The shielding portion may include a second shielding portion provided inthe mask sheet and shielding a portion of the plurality of openings inthe deposition region. The mask sheet may comprise the second shieldingportion.

The shielding portion may include: a first shielding portion including aportion of the thin shielding plate and protruding to the depositionregion; and a second shielding portion provided in the mask sheet andshielding a portion of the plurality of openings in the depositionregion. The mask sheet may comprise the second shielding portion.

The first shielding portion may at least partially overlap the secondshielding portion.

At least a portion of the second shielding portion may have a thicknessless than that of the mask sheet.

The depositing the deposition material may further comprise depositingthe deposition material on the display substrate in a vacuum.

The shielding portion may shield at least a portion of at least oneopening at a boundary of the deposition region.

The depositing the deposition material may further comprise depositingthe deposition material on a non-emission region of the displaysubstrate.

The mask sheet may comprise a material different from that of the thinshielding plate.

According to one or more embodiments, a method of manufacturing adisplay device includes: arranging a mask assembly such that the maskassembly faces a display substrate; applying a force to the maskassembly and directed toward the display substrate, by using a magneticfield generating unit; and forming a dummy intermediate layer above apixel-defining layer of the display substrate by emitting a depositionmaterial from a source unit, allowing the deposition material to passthrough the mask assembly, forming a plurality of intermediate layersover the display substrate, and forming a display area, wherein thedisplay area includes a shape other than a rectangle or a square.

The intermediate layer may have an area different from that of the dummyintermediate layer.

The dummy intermediate layer may have an area less than that of theintermediate layer.

The intermediate layer and the dummy intermediate layer may include thesame material.

The dummy intermediate layer may be arranged in a non-emission region.

According to one or more embodiments, a display device includes: adisplay substrate; a pixel-defining layer over the display substrate, aportion of the pixel-defining layer being open; an intermediate layer atthe open portion of the pixel-defining layer; and a dummy intermediatelayer above the pixel-defining layer.

The intermediate layer may have an area different from that of the dummyintermediate layer.

The dummy intermediate layer may have an area less than that of theintermediate layer.

The dummy intermediate layer may be arranged in a non-emission region.

The intermediate layer and the dummy intermediate layer may include thesame material.

The intermediate layer and the dummy intermediate layer may respectivelycomprise a plurality of intermediate layers and a plurality of dummyintermediate layers, the plurality of dummy intermediate layers beingarranged outside the plurality of intermediate layers.

The intermediate layer may comprise a plurality of intermediate layersspaced apart from each other and may form a display area having a shapeother than a rectangle or a square.

This general and specific aspect may be embodied by using a system, amethod, and a computer program, or a combination of a certain system, amethod, and a computer program.

Embodiments may deposit a shape which is not a rectangle or a square.Also, embodiments may improve deposition efficiency and depositionaccuracy by making a more uniform interval between a display substrateand a mask sheet.

Embodiments may minimize a deposition defect occurring duringdeposition.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a mask assembly according to anembodiment;

FIG. 2 is a plan view of a mask sheet and a thin shielding plateincluded in the mask assembly illustrated in FIG. 1;

FIG. 3 is a cross-sectional view of an apparatus for manufacturing adisplay device including the mask assembly illustrated in FIG. 1;

FIG. 4 is a plan view of a display device manufactured by the apparatusillustrated in FIG. 3;

FIG. 5 is a cross-sectional view of the display device of FIG. 4 takenalong a line V-V′ of FIG. 4;

FIG. 6 is a plan view illustrating the arrangement of an intermediatelayer and a dummy intermediate layer illustrated in FIG. 5;

FIG. 7 is a perspective view of a mask assembly according to anotherembodiment;

FIG. 8 is a plan view of a mask sheet and a thin shielding plateillustrated in FIG. 7;

FIG. 9 is a cross-sectional view of the mask sheet of FIG. 8 taken alonga line IX-IX′;

FIG. 10 is a cross-sectional view of an apparatus for manufacturing adisplay device including the mask assembly illustrated in FIG. 7;

FIG. 11 is a plan view illustrating the arrangement of an intermediatelayer and a dummy intermediate layer deposited by the apparatusillustrated in FIG. 10;

FIG. 12 is a perspective view of a mask assembly according to anotherembodiment;

FIG. 13 is a plan view of a mask sheet and a thin shielding plate of themask assembly illustrated in FIG. 12;

FIG. 14 is a cross-sectional view of an apparatus for manufacturing adisplay device, the apparatus including the mask assembly illustrated inFIG. 12; and

FIG. 15 is a plan view illustrating the arrangement of an intermediatelayer and a dummy intermediate layer deposited by the apparatusillustrated in FIG. 14.

DETAILED DESCRIPTION

As the inventive concept allows for various changes and numerousembodiments, exemplary embodiments will be illustrated in the drawingsand described in detail in the written description. An effect and acharacteristic of the inventive concept, and a method of accomplishingthese will be apparent when referring to embodiments described withreference to the drawings. This inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the exemplary embodiments set forth herein.

Hereinafter, the inventive concept will be described more fully withreference to the accompanying drawings, in which exemplary embodimentsof the inventive concept are shown. When description is made withreference to the drawings, like reference numerals in the drawingsdenote like or corresponding elements, and repeated description thereofwill be omitted.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items.

It will be understood that although the terms “first”, “second”, etc.may be used herein to describe various components, these componentsshould not be limited by these terms. These components are only used todistinguish one component from another.

As used herein, the singular forms “a” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be further understood that the terms “comprises” and/or“comprising” used herein specify the presence of stated features orcomponents, but do not preclude the presence or addition of one or moreother features or components.

It will be understood that when a layer, region, or component isreferred to as being “formed on,” another layer, region, or component,it can be directly or indirectly formed on the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. In other words, since sizes and thicknesses of componentsin the drawings are arbitrarily illustrated for convenience ofexplanation, the following embodiments are not limited thereto. Thevarious figures thus may not be to scale.

In the following examples, the x-axis, the y-axis and the z-axis are notlimited to three axes of the rectangular coordinate system, and may beinterpreted in a broader sense. For example, the x-axis, the y-axis, andthe z-axis may be perpendicular to one another, or may representdifferent directions that are not perpendicular to one another.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. All numerical values are approximate, and may vary. Allexamples of specific materials and compositions are to be taken asnonlimiting and exemplary only. Other suitable materials andcompositions may be used instead.

FIG. 1 is a perspective view of a mask assembly 150 according to anembodiment. FIG. 2 is a plan view of a mask sheet and a thin shieldingplate of the mask assembly illustrated in FIG. 1. FIG. 3 is across-sectional view of an apparatus 100 for manufacturing a displaydevice including the mask assembly illustrated in FIG. 1.

Referring to FIGS. 1 to 3, the mask assembly 150 may include mask frames151, a mask sheet 152, a thin shielding plate 153, and a support frame154.

In the mask assembly 150, the plurality of frames 151 may be connectedto each other such that spaces are formed therebetween.

At least two mask sheets 152 may be provided and installed on the maskframes 151 such that the mask sheets 152 are spaced apart from eachother. In this case, the mask sheets 152 may be arranged sequentiallyalong a first direction (e.g. Y-axis direction of FIG. 1).

A plurality of openings 152-1 may be arranged in the mask sheet 152 in alengthwise direction. In this case, the plurality of openings 152-1 maybe spaced apart from each other by a predetermined interval and maysubstantially occupy an entire surface of the mask sheet 152.

The plurality of openings 152-1 may include first openings 152-1A insidea deposition region S, and second openings 152-1B at an edge of thedeposition region S.

The thin shielding plate 153 may be installed on the mask frame 151. Inthis case, the thin shielding plate 153 may be a plurality of thinshielding plates, which may be installed on the mask frame 151 such thatthe thin shielding plates 153 are spaced apart from each other. Thedeposition region S may be defined by an area between the thin shieldingplates 153. Particularly, the deposition region S may have a shape otherthan a rectangle or a square. For example, the shape of the depositionregion S in plan view may be a triangle, a polygon, an ellipse, or acircle.

The thin shielding plate 153 may include a thin shielding plate bodyportion 153-1 installed on the mask frame 151, and a first shieldingportion 153-2 protruding from the thin shielding plate body portion153-1.

The thin shielding plate body portion 153-1 may include a straightline-shaped or linear plate. In this case, the thin shielding plate bodyportion 153-1 may be arranged in a direction (or a first direction)perpendicular to a lengthwise direction of the mask sheet 152, e.g. toextend along the Y-axis direction of FIG. 1.

The first shielding portion 153-2 may protrude in a lengthwise directionof the mask sheet 152 from the thin shielding plate body portion 153-1.In this case, the first shielding portion 153-2 may define an edge ofthe shape of the deposition region S with the thin shielding plate bodyportion 153-1. Particularly, the first shielding portion 153-2 maydefine a portion of the edge of the deposition region S, and may form apredetermined angle with the thin shielding plate body portion 153-1, acurved portion, etc.

The first shielding portion 153-2 may shield a portion of the pluralityof openings 152-1 in the deposition region S. For example, the firstshielding portion 153-2 may shield a portion of the second openings152-1 B near the edge (or the boundary) of the deposition region S. Inthis case, a deposition material may pass through only a portion of thesecond openings 152-1B.

The thin shielding plate 153 and the mask sheet 152 may includematerials different from each other. For example, the thin shieldingplate 153 may include austenitic stainless steels, and the mask sheet152 may include a nickel-steel alloy (Invar).

The thin shielding plate 153 and the mask sheet 152 may be fixed to themask frame 151 while the thin shielding plate 153 and the mask sheet 152are extended. In this case, the thin shielding plate 153 and the masksheet 152 may be fixed to the mask frame 151 via welding.

A support frame 154 may be between adjacent mask sheets 152. Both endsof the support frame 154 may be inserted into the mask frame 151. Inthis case, the support frame 154 may shield an interval between the masksheets 152 and may also support the mask sheets 152, thereby preventingsagging of the mask sheets 152.

An apparatus 100 for manufacturing a display device may include achamber 110, a first support 120, a second support 130, the maskassembly 150, a source unit 140, a magnetic field generating unit 160, avision unit 170, and a pressure adjustor 180.

The chamber 110 may include a space therein, and the chamber 110 mayhave an opening. In this case, a gate valve 110-1 may be installed onthe opening of the chamber 110 and the chamber 110 may be opened orclosed by an operation of the gate valve 110-1.

The first support 120 may seat a display substrate D thereon and supportthe display substrate D. In this case, the first support 120 may have abracket form and be fixed inside the chamber 110. In another embodiment,the first support 120 may have a shuttle form which may seat the displaysubstrate D thereon, and may move linearly inside the chamber 110.Hereinafter, for convenience of description, a case of the first support120 having a bracket form and being fixed inside the chamber 110 ismainly described.

The second support 130 may seat the mask assembly 150 thereon. In thiscase, the second support 130 may be inside the chamber 110. The secondsupport 130 may fine-adjust the location of the mask assembly 150. Inthis case, the second support 130 may include a separate driver oralignment unit, etc. for moving the mask assembly 150 in differentdirections.

The source unit 140 may face the mask assembly 150. In this case, thesource unit 140 may receive a deposition material and evaporate orsublimate the deposition material by applying heat to the depositionmaterial.

The magnetic field generating unit 160 may be inside the chamber 110 andmay face the display substrate D. In this case, the magnetic fieldgenerating unit 160 may apply force to the mask assembly 150 through thedisplay substrate D by applying magnetic force to the mask sheet 152.Particularly, the magnetic field generating unit 160 may not onlyprevent sagging of the mask sheet 152 but may also allow the mask sheet152 to approach the display substrate D. Also, the magnetic fieldgenerating unit 160 may maintain a uniform interval between the masksheet 152 and the display substrate D with respect to the lengthwisedirection of the mask sheet 152.

The vision unit 170 may be installed on the chamber 110 and may capturelocations of the display substrate D and the mask assembly 150. In thiscase, the vision unit 170 may include a camera capturing the displaysubstrate D and the mask assembly 150. The locations of the displaysubstrate D and the mask assembly 150 may be recognized based on animage captured by the vision unit 170. The second support 130 may thenfine-adjust the location of the mask assembly 150 based on the image.

The pressure adjuster 180 may be connected to the chamber 110, and mayadjust the pressure of the atmosphere inside of the chamber 110. Forexample, the pressure adjustor 180 may adjust the pressure of the insideof the chamber 110 to a pressure level the same as or similar toatmospheric pressure. Also, the pressure adjustor 180 may adjust thepressure of the inside of the chamber 110 to a level the same as orsimilar to that of a vacuum state.

The pressure adjustor 180 may include a connection pipe 181 connected tothe chamber 110, and a pump 182 installed on the connection pipe 181. Inthis case, external air may be introduced via the connection pipe 181,or a gas inside the chamber 110 may be guided to the outside via theconnection pipe 181 depending on an operation of the pump 182.

Meanwhile, the apparatus 100 for manufacturing the display device may beused to manufacture a display device (not shown) which will be describedbelow. When the pressure adjustor 180 adjusts the pressure of the insideof the chamber 110 to a level the same as or similar to atmosphericpressure, the gate valve 110-1 may operate to open the chamber 110.

After that, the display substrate D may be inserted from the outside ofthe chamber 110 into the inside of the chamber 110. In this case, thedisplay substrate D may be inserted into the chamber 110 by variousmethods. For example, the display substrate D may be inserted from theoutside of the chamber 110 into the inside of the chamber 110 via arobot arm, etc. provided outside the chamber 110. In another embodiment,in the case where the first support 120 has a shuttle form, the firstsupport 120 is carried out from the inside of the chamber 110 to theoutside of the chamber 110, and then the display substrate D is seatedabove the first support 120 via a separate robot arm, etc. providedoutside the chamber 110. Subsequently, the first support 120 is insertedfrom the outside of the chamber 110 into the inside of the chamber 110.Hereinafter, for convenience of description, a case where the displaysubstrate D is inserted from the outside of the chamber 110 into theinside of the chamber 110 via a robot arm provided outside the chamber110 is mainly described.

The mask assembly 150 may be inside the chamber 110 as described above.In another embodiment, like or similar to the display substrate D, themask assembly 150 may be inserted from the outside of the chamber 110into the inside of the chamber 110. However, hereinafter, forconvenience of description, a case where only the display substrate D isinserted from the outside of the chamber 110 into the inside of thechamber 110 with the mask assembly 150 already inside the chamber 110 ismainly described.

When the display substrate D is inserted into the inside of the chamber110, the display substrate D may be seated above the first support 120.In this case, the vision unit 170 may capture the locations of thedisplay substrate D and the mask assembly 150. Particularly, the visionunit 170 may capture a first align mark of the display substrate D and asecond align mark of the mask assembly 150.

The locations of the display substrate D and the mask assembly 150 maybe recognized based on the captured first align mark and the capturedsecond align mark. In this case, the apparatus 100 for manufacturing thedisplay device may include a separate controller (not shown) and mayrecognize the locations of the display substrate D and the mask assembly150.

When the locations of the display substrate D and the mask assembly 150have been recognized, the second support 130 may fine-adjust thelocation of the mask assembly 150.

After that, the source unit 140 may operate and supply the depositionmaterial to the mask assembly 150. The deposition material that haspassed through the plurality of openings 152-1 may be deposited on thedisplay substrate D. In this case, the pump 182 may maintain thepressure of the inside of the chamber 110 at a level the same as orsimilar to that of a vacuum state, by drawing out a gas of the inside ofthe chamber 110 and discharging the same.

In the above case, the deposition material may pass through the firstopenings 152-1A in the deposition region S, and may be deposited on thedisplay substrate D. Also, the deposition material may pass through aportion of the second openings 152-1B at the edge of the depositionregion S, and may be deposited on the display substrate D. In this case,the deposition region S may have a shape excluding, or different from, arectangle or a square.

Therefore, the mask assembly 150, the apparatus 100 for manufacturingthe display device, and a method of manufacturing the display device maybe used to deposit a display area having a shape other than a rectangleor a square on the display substrate D.

Hereinafter, the display device manufactured via the mask assembly 150,the apparatus 100 for manufacturing the display device, and the methodof manufacturing the display device are described.

FIG. 4 is a plan view of a display device manufactured by the apparatusillustrated in FIG. 3. FIG. 5 is a cross-sectional view of the displaydevice of FIG. 4 taken along a line V-V′ of FIG. 4. FIG. 6 is a planview illustrating the arrangement of an intermediate layer and a dummyintermediate layer illustrated in FIG. 5.

Referring to FIGS. 4 to 6, a display area DA above a substrate 21, and anon-display area NDA around the display area DA, may be defined in thedisplay device 20. An emission portion may be in the display area DA,and a power wiring (not shown), etc. may be in the non-display area NDA.Also, a pad portion C may be in the non-display area NDA.

The display device 20 may include the display substrate D, anintermediate layer 28-2 and a dummy intermediate layer O on the displaysubstrate D, as well as an opposite electrode 28-3 on the intermediatelayer 28-2 and the dummy intermediate layer O. Also, the display device20 may include a thin film encapsulation layer E above the oppositeelectrode 28-3.

The display substrate D may include the substrate 21, a thin filmtransistor (TFT), a passivation layer 27, and a pixel electrode 28-1.

The substrate 21 may include a plastic material and may include ametallic material such as steel use stainless (SUS) or Ti. Also, thesubstrate 21 may include polyimide (PI). Hereinafter, for convenience ofdescription, a case where the substrate 21 includes PI is mainlydescribed.

The TFT may be above the substrate 21, the passivation layer 27 maycover the TFT, and an organic light-emitting diode (OLED) 28 may beabove the passivation layer 27.

A buffer layer 22 including an organic compound and/or an inorganiccompound is deposited above the substrate 21. The buffer layer 22 mayinclude SiOx (x≥1) and SiNx (x≥1).

After an active layer 23 is formed above the buffer layer 22 in apredetermined pattern, the active layer 23 is covered by a gateinsulating layer 24. The active layer 23 may include a source region23-1 and a drain region 23-3, and may further include a channel region23-2 therebetween.

The active layer 23 may include various materials. For example, theactive layer 23 may include an inorganic semiconductor material such asamorphous silicon or crystalline silicon. As another example, the activelayer 23 may include an oxide semiconductor. As another example, theactive layer 23 may include an organic semiconductor material. However,hereinafter, for convenience of description, a case where the activelayer 23 includes amorphous silicon is mainly described.

The active layer 23 may be formed by forming an amorphous silicon layerabove the buffer layer 22, crystallizing the amorphous silicon layer toform a polycrystalline silicon layer, and patterning the polycrystallinesilicon layer. The source region 23-1 and the drain region 23-3 of theactive layer 23 are doped with impurities depending on a type of theTFT, such as a driving TFT (not shown) or a switching TFT (not shown).

A gate electrode 25 corresponding to the active layer 23, and aninterlayer insulating layer 26 covering the gate electrode 25, areformed above the gate insulating layer 24.

Also, contact holes H1 are formed in the interlayer insulating layer 26and the gate insulating layer 24. Then, a source electrode 27-1 and adrain electrode 27-2 are formed above the interlayer insulating layer 26such that the source electrode 27-1 and the drain electrode 27-2respectively contact the source region 23-1 and the drain region 23-3through the contact holes H1.

The passivation layer 27 is formed above the TFT, and the pixelelectrode 28-1 of the OLED 28 is formed above the passivation layer 27.The pixel electrode 28-1 contacts the drain electrode 27-2 of the TFTthrough a via hole H2 formed in the passivation layer 27. Thepassivation layer 27 may include a single layer or two or more layersincluding an inorganic material and/or an organic material. Thepassivation layer 27 may include a planarization layer having an upperflat surface regardless of bending of a lower layer, or it may be bentin accordance with bending of a layer located therebelow. Also, thepassivation layer 27 may include a transparent insulating layer, andthus may have a resonance effect.

After the pixel electrode 28-1 is formed above the passivation layer 27,a pixel-defining layer 29 including an organic material and/or aninorganic material is formed so as to cover the pixel electrode 28-1 andthe passivation layer 27. The pixel electrode 28-1 is exposed.

Also, the intermediate layer 28-2 and the opposite electrode 28-3 areformed above at least the pixel electrode 28-1. In another embodiment,the opposite electrode 28-3 may be formed above an entire surface of thedisplay substrate D. In this case, the opposite electrode 28-3 may beformed above the intermediate layer 28-2, the pixel-defining layer 29,and the dummy intermediate layer O. Hereinafter, for convenience ofdescription, a case where the opposite electrode 28-3 is formed abovethe intermediate layer 28-2, the pixel-defining layer 29, and the dummyintermediate layer O is mainly described.

The pixel electrode 28-1 serves as an anode electrode, and the oppositeelectrode 28-3 serves as a cathode electrode. The polarities of thepixel electrode 28-1 and the opposite electrode 28-3 may, however, bereversed.

The pixel electrode 28-1 and the opposite electrode 28-3 are insulatedfrom each other by the intermediate layer 28-2, and light is emittedfrom an organic emission layer by applying voltages of differentpolarities to the intermediate layer 28-2.

The intermediate layer 28-2 may include the organic emission layer. Asan embodiment, the intermediate layer 28-2 may include the organicemission layer and further include at least one of a hole injectionlayer (HIL), a hole transport layer (HTL), an electron transport layer(ETL), and an electron injection layer (EIL). Embodiments are notlimited thereto, however, and the intermediate layer 28-2 may forinstance include the organic emission layer and further include variousfunctional layers (not shown).

In this case, the intermediate layer 28-2 may be formed by theabove-described apparatus (not shown) for manufacturing the displaydevice.

Also, the dummy intermediate layer O may be formed above thepixel-defining layer 29 when forming the intermediate layer 28-2. Whilethe deposition material that has passed through the first openings152-1A is deposited on the display substrate D and forms theintermediate layer 28-2, the deposition material that has passed throughthe second openings 152-1B may be deposited on the display substrate Dand may form the dummy intermediate layer O.

In this case, the dummy intermediate layer O and the intermediate layer28-2 may include the same material. Particularly, each of the dummyintermediate layer O and the intermediate layer 28-2 may include atleast one of an organic emission layer, an HIL, an HTL, an ETL, an EIL,and a function layer.

The intermediate layer 28-2 may be provided as a plurality ofintermediate layers 28-2, and the plurality of intermediate layers 28-2may form a display area DA. Particularly, the plurality of intermediatelayers 28-2 may form the display DA in a shape other than a rectangle ora square. In this case, the plurality of intermediate layers 28-2 may bespaced apart from each other inside the display area DA.

The dummy intermediate layer O may be provided as a plurality of dummyintermediate layers O which may be arranged at the edge (or theboundary) of the display area DA. Particularly, the plurality of dummyintermediate layers O may be arranged outside the plurality ofintermediate layers 28-2. In this case, the plurality of dummyintermediate layers O may be arranged in the non-display area NDA.Therefore, the dummy intermediate layers O may not emit light.

At least one of the dummy intermediate layers O may have an areadifferent from that of one of the intermediate layers 28-2.Particularly, at least one of the dummy intermediate layers O may havean area less than that of the intermediate layer 28-2. The area of atleast one of the second openings 152-1B may be less than that of one ofthe first openings 152-1A due to the first shielding portion 153-2. Inthis case, a deposition material that has passed through the secondopening 152-1B partially shielded by the first shielding portion 153-2is deposited on an area less than the area of the intermediate layer28-2, to form a smaller dummy intermediate layer O.

Meanwhile, one unit pixel includes a plurality of sub-pixels. Theplurality of sub-pixels may emit light of various colors. For example,the plurality of sub-pixels may include sub-pixels respectively emittingred, green, and blue light and may include sub-pixels (not shown)respectively emitting red, green, blue, and white light.

The sub-pixel may include one intermediate layer 28-2. In this case, inthe case of forming one sub-pixel, the intermediate layer 28-2 and thedummy intermediate layer O may be formed by the above-describedapparatus 100 for manufacturing the display device.

Meanwhile, the thin film encapsulation layer E may include a pluralityof inorganic layers, or an inorganic layer and an organic layer.

The organic layer of the thin film encapsulation layer E includes apolymer and may include a single layer or stacked layers including oneof polyethylene terephthalate (PET), PI, polycarbonate (PC), epoxy,polyethylene (PE), and polyacrylate. The organic layer may includepolyacrylate. The organic layer may include a polymerized monomercomposition including a diacrylate-based monomer and a triacrylate-basedmonomer. The monomer composition may further include amonoacrylate-based monomer. Also, the monomer composition may furtherinclude a well-known photoinitiator such as trimethyl benzoyl diphenylphosphine oxide (TPO), but embodiments of the inventive concept are notlimited thereto.

The inorganic layer of the thin film encapsulation layer E may be asingle layer or stacked layers including one of a metallic oxide or ametallic nitride. The inorganic layer may include one of SiNx, A₂O₃,SiO₂, and TiO₂.

An uppermost layer of the thin film encapsulation layer E is exposed,and may thus include an inorganic layer to prevent moisture transmissioninto the OLED.

The thin film encapsulation layer E may include at least one sandwichstructure in which at least one organic layer is inserted between atleast two inorganic layers. As another example, the thin filmencapsulation layer E may include at least one sandwich structure inwhich at least one inorganic layer is inserted between at least twoorganic layers. As a further example, the thin film encapsulation layerE may include at least one sandwich structure in which at least oneorganic layer is inserted between at least two inorganic layers, and mayalso include at least one sandwich structure in which at least oneinorganic layer is inserted between at least two organic layers.

The thin film encapsulation layer E may include a first inorganic layer,a first organic layer, and a second inorganic layer sequentiallyarranged over the OLED.

As another example, the thin film encapsulation layer E may include afirst inorganic layer, a first organic layer, a second inorganic layer,a second organic layer, and a third inorganic layer sequentiallyarranged over the OLED.

As another example, the thin film encapsulation layer E may include afirst inorganic layer, a first organic layer, a second inorganic layer,a second organic layer, a third inorganic layer, a third organic layer,and a fourth inorganic layer sequentially arranged over the OLED.

In addition, a halogenated metallic layer including LiF may be includedbetween the OLED and the first inorganic layer. The halogenated metalliclayer may prevent the OLED from being damaged when the first inorganiclayer is sputtered thereon.

The first organic layer may have an area less than that of the secondinorganic layer. The second organic layer may have an area less thanthat of the third inorganic layer.

Therefore, the display device 20 may implement a display area having ashape other than a rectangle or a square.

FIG. 7 is a perspective view of a mask assembly 150A according toanother embodiment. FIG. 8 is a plan view of a mask sheet and a thinshielding plate illustrated in FIG. 7. FIG. 9 is a cross-sectional viewof the mask sheet taken along a line IX-IX′ of FIG. 8. FIG. 10 is across-sectional view of an apparatus 100A for manufacturing a displaydevice including the mask assembly 150A illustrated in FIG. 7. FIG. 11is a plan view illustrating the arrangement of an intermediate layer anda dummy intermediate layer deposited by the apparatus 100A illustratedin FIG. 10.

Referring to FIGS. 7 to 11, the mask assembly 150A may include a maskframe 151A, a mask sheet 152A, a thin shielding plate 153A, and asupport frame 154A.

In this case, since the mask frame 151A and the support frame 154A aresubstantially the same as those described above, descriptions thereofare omitted.

The mask sheet 152A may include a plurality of openings 152A-1. In thiscase, the plurality of openings 152A-1 may be formed across an entiresurface of the mask sheet 152A in a lengthwise direction of the masksheet 152A.

The mask sheet 152A may include a second shielding portion 152A-3shielding a portion of the plurality of openings 152A-1. In this case,the second shielding portion 152A-3 may have a thickness different fromthat of the rest of the mask sheet 152A. For example, the secondshielding portion 152A-3 may have a thickness less than that of the masksheet 152A in which the openings 152A-1 are formed.

A portion of the openings 152A-1 facing the support frame 154A may beformed by etching. The openings 152A-1 may be formed by performingetching twice when needed. In this case, one side of the secondshielding portion 152A-3 may be formed after the first etching is madewhen forming the openings 152A-1. Therefore, the second shieldingportion 152A-3 may have a thickness less than that of the rest of masksheet 152A.

A method of manufacturing the mask sheet 152A is described below. First,a preform for manufacturing the mask sheet 152A may be prepared. Afterthat, an open pattern may be formed in a photoresist by coating thephotoresist on the preform and exposing the photoresist. In this case,the photoresist may be arranged over a portion of the preform in whichthe second shielding portion 152A-3 is to be formed, and may completelyshield that portion of the preform.

Also, an etching solution may be sprayed, or a laser may be irradiatedonto the preform after the open pattern is formed in the photoresist viaexposure. In this case, the etching solution or the laser may reach thepreform via the open pattern, and etch one side of the preform.

After that, the photoresist is removed, and a resin may be coated on oneside of the etched preform. A photoresist is coated again on a sideopposite to the side of the preform on which the resin has been coated,and an open pattern may be formed in the photoresist. In this case,portions of the preform in which the second shielding portion 152A-3 andthe openings 152A-1 are to be formed may be exposed.

After that, the openings 152A-1 and the second shielding portions 152A-3may be formed by removing the photoresist and the resin, and thenetching the exposed preform.

The second shielding portion 152A-3 may be provided as a plurality ofsecond shielding portions 152A-3. In this case, the plurality of secondshielding portions 152A-3 may be spaced apart from each other. Forexample, the plurality of second shielding portions 152A-3 may be spacedapart from each other in the width direction of the mask sheet 152A.Also, the plurality of second shielding portions 152A-3 may be spacedapart from each other in the lengthwise direction of the mask sheet152A. Particularly, from among the plurality of second shieldingportions 152A-3, the second shielding portions 152A-3 spaced apart fromeach other in the lengthwise direction of the mask sheet 152A may definethe deposition region S together with the thin shielding plate 153A.

The thin shielding plate 153A may have the form of a plate with a flatshape. In this case, the thin shielding plate 153A may be provided as aplurality of thin shielding plates 153A, and the plurality of thinshielding plates 153A may be spaced apart from each other in thelengthwise direction of the mask sheet 152A.

The deposition region S defined by the thin shielding plate 153A and thesecond shielding portion 152A-3 may have a shape other than a square ora rectangle.

Meanwhile, the apparatus 100A for manufacturing the display device mayinclude a chamber 110A, a first support 120A, a second support 130A, themask assembly 150A, a source unit 140A, a magnetic field generating unit160A, a vision unit 170A, and a pressure adjustor 180A. In this case,since the chamber 110A, the first support 120A, the second support 130A,the source unit 140A, the magnetic field generating unit 160A, thevision unit 170A, and the pressure adjustor 180A are the same as orsimilar to those described above, descriptions thereof are omitted.

A method of manufacturing a display device is now described. First, thedisplay substrate D is inserted into the chamber 110A and then the maskassembly 150A is arranged to face the display substrate D.

After that, the locations of the mask assembly 150A and the displaysubstrate D are recognized via the vision unit 170A, and then the maskassembly 150A and the display substrate D may be aligned via the secondsupport 130A.

The magnetic field generating unit 160A may apply magnetic force to themask assembly 150A, thereby coupling the mask sheet 152A to the displaysubstrate D. In this case, the magnetic field generating unit 160A mayapply magnetic force to the mask sheet 152A. Particularly, in the casewhere the boundary portion of the thin shielding plate 153A overlaps theopenings 152A-1, magnetic force applied to the mask sheet 152A by themagnetic field generating unit 160A may be weakened or repulsive forcemay occur at the boundary portion of the thin shielding plate 152A. Inthis case, the second shielding portion 152A-3 may remove the repulsiveforce occurring at the boundary portion of the thin shielding plate153A, by shielding a portion of the plurality of openings 152A-1 at theboundary portion of the thin shielding plate 153A. That is, the magneticfield generating unit 160A may partially cancel the repulsive forceoccurring at the boundary portion of the thin shielding plate 152A byapplying attractive force to the second shielding portion 152A-3.

The source unit 140A may operate and supply the deposition material tothe display substrate D. In this case, the deposition material may passthrough the openings 152A-1 of the mask sheet 152A and may be depositedon the display substrate D.

The deposition material deposited on the display substrate D may formthe dummy intermediate layer O and the intermediate layer 28-2. In thiscase, the dummy intermediate layer O and the intermediate layer 28-2 maybe provided as a plurality of dummy intermediate layers O and aplurality of intermediate layers 28-2, respectively, and the pluralityof intermediate layers 28-2 may form the display area DA. Particularly,the display area DA may have a shape other than a square or a rectangleas described above.

At least one of the plurality of dummy intermediate layers O may have anarea equal to or less than the area of the intermediate layer 28-2. Inthis case, the plurality of dummy intermediate layers O may be arrangedoutside the plurality of intermediate layers 28-2. Particularly, theplurality of dummy intermediate layers O may be arranged in thenon-display area NDA and thus may not emit light.

Therefore, the mask assembly 150A, the apparatus 100A for manufacturingthe display device, and the method of manufacturing the display devicemay be used to deposit a shape which is not a rectangle or a square.Also, the mask assembly 150A, the apparatus 100A for manufacturing thedisplay device, and the method of manufacturing the display device mayimprove deposition efficiency and deposition accuracy by making a moreuniform interval between the display substrate D and the mask sheet152A. The mask assembly 150A, the apparatus 100A for manufacturing thedisplay device, and the method of manufacturing the display device maybe used together to minimize deposition defects occurring duringdeposition.

FIG. 12 is a perspective view of a mask assembly 150B according toanother embodiment. FIG. 13 is a plan view of a mask sheet 152B and athin shielding plate 153B illustrated in FIG. 12. FIG. 14 is across-sectional view of an apparatus for manufacturing a display device,the apparatus including the mask assembly illustrated in FIG. 12. FIG.15 is a plan view illustrating the arrangement of an intermediate layerand a dummy intermediate layer deposited by the apparatus illustrated inFIG. 14.

Referring to FIGS. 12 to 15, the mask assembly 150B may include a maskframe 151B, the mask sheet 152B, the thin shielding plate 153B, and asupport frame 154B. In this case, since the mask frame 151B and thesupport frame 154B are the same as or similar to those described above,descriptions thereof are omitted.

At least one of the mask sheet 152B and the thin shielding plate 153Bmay include a shielding portion (not shown) defining a deposition regionS. In this case, the shielding portion may include a first shieldingportion 153B-2 of the thin shielding plate 153B, and a second shieldingportion 152B-3 of the mask sheet 152B.

The mask sheet 152B may include a plurality of openings 152B-1. In thiscase, the plurality of openings 152B-1 may be spaced apart from eachother by a predetermined interval in the lengthwise direction of themask sheet 152B. Also, the plurality of openings 152B-1 may be formedacross the entire surface of the mask sheet 152B in the lengthwisedirection of the mask sheet 152B.

The second shielding portion 152B-3 may shield a portion of theplurality of openings 152B-1. In this case, the second shielding portion152B-3 may shield at least one opening 152B-1 arranged at the boundaryof the first shielding portion 153B-2.

The thin shielding plate 153B may be provided as a plurality of thinshielding plates 153B, and the plurality of thin shielding plates 153Bmay be spaced apart from each other in the lengthwise direction of themask sheet 152B. Particularly, the plurality of thin shielding plates153B may define one display area DA with the support frame 1546 arrangedbetween the mask sheets 1526.

The thin shielding plate 153B may include a thin shielding plate bodyportion 153B-1 formed in a flat shape, and the first shielding portion153B-2 protruding from the thin shielding plate body portion 153B-1. Thefirst shielding portion 153B-2 may protrude between adjacent thinshielding plates 153B. In this case, the first shielding portions 153B-2of the adjacent thin shielding plates 1536 may face each other.

At least a portion of the first shielding portion 153B-2 may overlap atleast a portion of the second shielding portion 152B-3. The firstshielding portion 153B-2 may be arranged at an edge portion of thesecond shielding portion 152B-3. The edge portion of the first shieldingportion 153B-2 may be arranged inside a region of the second shieldingportion 152B-3. Particularly, in this case, a portion of the secondshielding portion 152B-3 may overlap the first shielding portion 153B-2,and another portion of the second shielding portion 152B-3 may protrudeinto the deposition area S rather than the first shielding portion153B-2.

At least a portion of the second shielding portion 152B-3 may have athickness different from that of the mask sheet 152B. At least a portionof the second shielding portion 152B-3 may have a thickness less thanthat of the mask sheet 152B. In this case, since a method of forming thethickness of the second shielding portion 152B-3 is the same as orsimilar to the method described above, a description thereof is omitted.

The apparatus 1006 for manufacturing the display device may include achamber 1106, a first support 1206, a second support 1306, the maskassembly 1506, a source unit 1406, a magnetic field generating unit1606, a vision unit 1706, and a pressure adjustor 1806. In this case,since the chamber 1106, the first support 1206, the second support 130B,the source unit 140B, the magnetic field generating unit 160B, thevision unit 170B, and the pressure adjustor 180B are the same as orsimilar to those described above, descriptions thereof are omitted.

A method of manufacturing a display device is now described. First, thedisplay substrate D is inserted into the chamber 1106 and then the maskassembly 150B may be arranged to face the display substrate D. Also, themask assembly 150B and the display substrate D may be captured via thevision unit 170B and then the mask assembly 150B and the displaysubstrate D may be aligned.

When alignment of the display substrate D with the mask assembly 150B iscompleted, the magnetic field generating unit 160B and the source unit140B may operate. In this case, the magnetic field generating unit 160Bmay couple the mask assembly 150B to the display substrate D. In thiscase, magnetic force from the magnetic field generating unit 160B maymove the mask sheet 152B toward the display substrate D. In this case,when the boundary of the thin shielding plate 153B overlaps the openings152B-1, repulsive force may occur at the boundary of the thin shieldingplate 153B on the upper surface of the thin shielding plate 153B. Inthis case, separation at the boundary between the mask sheet 152B andthe display substrate D may occur further than at other portions, andthe deposition materials that have passed through the openings 152B-1may be deposited on the display substrate D with a deposition patternthat may not be uniform. However, the magnetic field generating unit160B may apply attractive force to the first shielding portion 153B-2,thereby solving the problem created by the repulsive force explainedabove. Particularly, the first shielding portion 153B-2 may allow thedeposition materials to be more uniformly deposited on the displaysubstrate D, by preventing the display substrate D and the mask sheet152B from being floated at the portion of the second shielding portion152B-3. Also, the first shielding portion 153B-2 may prevent depositiondefects from occurring at the display substrate D.

In the case of depositing the deposition material on the displaysubstrate D as described above, the dummy intermediate layer O and theintermediate layer 28-2 may be formed on the display substrate D. Inthis case, the dummy intermediate layer O and the intermediate layer28-2 may respectively be provided as a plurality of dummy intermediatelayers O and a plurality of intermediate layers 28-2, spaced apart fromeach other.

At least one of the plurality of dummy intermediate layers O may have anarea less than that of one of the plurality of intermediate layers 28-2.Particularly, the dummy intermediate layer O deposited via the openings152B-1 arranged at the boundary of at least one of the first shieldingportion 153B-2 and the second shielding portion 152B-3 may have an arealess than the area of the intermediate layer 28-2.

When the plurality of intermediate layers 28-2 and the dummyintermediate layers O are formed as described above, the plurality ofintermediate layers 28-2 may form the display area DA. In this case, theplurality of dummy intermediate layers O may be arranged in thenon-display area NDA, which is outside the display area DA. Also, thedisplay area DA may have a shape other than a square or a rectangle.

Therefore, the mask assembly 150B, the apparatus 1008 for manufacturingthe display device, and the method of manufacturing the display devicemay be used to deposit a shape which is not a rectangle or a square.Also, the mask assembly 150B, the apparatus 1008 for manufacturing thedisplay device, and the method of manufacturing the display device mayimprove deposition efficiency and deposition accuracy by making a moreuniform interval between the display substrate D and the mask sheet152B. The mask assembly 150B, the apparatus 1008 for manufacturing thedisplay device, and the method of manufacturing the display device maybe used to minimize deposition defects occurring during deposition.

Though the inventive concept has been described with reference to theembodiments illustrated in the drawings, this is merely for illustrativepurposes and it will be understood by those of ordinary skill in the artthat various changes in form and details and equivalents thereof may bemade therein without departing from the spirit and scope of theinventive concept as defined by the following claims. Various featuresof the above described and other embodiments can be mixed and matched inany manner, to produce further embodiments consistent with theinvention.

What is claimed is:
 1. A method of manufacturing a display device, themethod comprising: arranging a mask assembly such that the mask assemblyfaces a display substrate; applying a force to the mask assembly anddirected toward the display substrate, by using a magnetic fieldgenerating unit; and emitting a deposition material from a source unitso that the deposition material passes through the mask assembly, anddepositing the deposition material on the display substrate, wherein themask assembly comprises: a mask frame; at least two mask sheetsinstalled on the mask frame, each of the mask sheets comprising aplurality of openings; and at least two thin shielding plates installedon the mask frame such that the thin shielding plates are spaced apartfrom each other and shield a portion of the plurality of openings ofeach mask sheet, and wherein one of the mask sheets and the thinshielding plates comprises a shielding portion between the thinshielding plates spaced apart from each other, the shielding portionselectively blocking at least portions of the openings so as to form adeposition region having a shape other than a rectangle or a square. 2.The method of claim 1, wherein the shielding portion comprises a firstshielding portion including a portion of the thin shielding plate andprotruding to the deposition region.
 3. The method of claim 1, whereinthe shielding portion comprises a second shielding portion shielding aportion of the plurality of openings in the deposition region, the masksheet comprising the second shielding portion.
 4. The method of claim 3,wherein at least a portion of the second shielding portion has athickness less than that of the mask sheet.
 5. The method of claim 1,wherein the shielding portion comprises: a first shielding portionincluding a portion of the thin shielding plate and protruding to thedeposition region; and a second shielding portion shielding a portion ofthe plurality of openings in the deposition region, the mask sheetcomprising the second shielding portion.
 6. The method of claim 5,wherein the first shielding portion at least partially overlaps thesecond shielding portion.
 7. The method of claim 1, wherein thedepositing the deposition material further comprises depositing thedeposition material on the display substrate in a vacuum.
 8. The methodof claim 1, wherein the shielding portion shields at least a portion ofat least one opening in at boundary of the deposition region.
 9. Themethod of claim 1, wherein the depositing the deposition materialfurther comprises depositing the deposition material on a non-emissionregion of the display substrate.
 10. The method of claim 1, wherein themask sheet comprises a material different from that of the thinshielding plate.
 11. A method of manufacturing a display device, themethod comprising: arranging a mask assembly such that the mask assemblyfaces a display substrate; applying a force to the mask assembly anddirected toward the display substrate, by using a magnetic fieldgenerating unit; and forming a dummy intermediate layer above apixel-defining layer of the display substrate while emitting adeposition material from a source unit, allowing the deposition materialto pass through the mask assembly, forming a plurality of intermediatelayers over the display substrate, and forming a display area, whereinthe display area comprises a shape other than a rectangle or a square.12. The method of claim 11, wherein the intermediate layer has an areadifferent from that of the dummy intermediate layer.
 13. The method ofclaim 12, wherein the dummy intermediate layer has an area less thanthat of the intermediate layer.
 14. The method of claim 11, wherein theintermediate layer and the dummy intermediate layer comprise the samematerial.
 15. The method of claim 11, wherein the dummy intermediatelayer is arranged in a non-emission region.